Edible waste oil to biofuel using reclaimable g-C3N4/HAp/Fe3O4/K2CO3 nanobiocomposite catalyst: Toxicity evaluation and optimization

In the current work, the new heterogeneous nonobiocomposite of g-C3N4/HAp/Fe3O4/K2CO3 was made from chicken bone and melamine and used in biofuel generation from edible waste oil (EWO). FTIR, SEM, Map-EDX, BET, VSM, and XRD techniques confirmed that the catalyst was synthesized. The magnetic saturation number and the BET value of g-C3N4/HAp/Fe3O4/K2CO3 were determined to be 8.89 emu.g-1 and 3.95 m2.g-1, respectively. The impact of temperature, time, catalyst mass, and the ratio of methanol: Oil (MeOH: Oil) on biofuel production was explored using response surface method-central composite design. The maximum yield of biofuel from EWO (98.52%) achieved at contact time of 150 min, temperature of 65 oC, catalyst amount of 3 wt%, and MeOH: Oil ratio of 15:1. Activation energy and k0 for the transesterification process were computed to be 58.91 kJ.mol-1 and 3.24×107 min-1, respectively. The values of ΔH and ΔG were determined positive for the biofuel production process, which indicates that the biofuel production process is exothermic and non-spontaneous. The value of the environmental factor (E) also showed that biofuel production has negligible harmful effects on the environment. The heterogeneous catalyst can be effectively reused many times in the transesterification process. The produced biofuel was in good compliance with famous standards and can serve as a suitable fuel source.